Reported need for and access to oral health care services during the COVID-19 pandemic in Canada.

Background: The COVID-19 pandemic interrupted routine and preventive dental services until precautions could be implemented to limit virus transmission. Access to services for dental emergencies was maintained. The objective of this study was to describe the reported need for, access to, and receipt of oral health care in Canada during the first year of the pandemic. Data and methods: The 2021 Survey on Access to Health Care and Pharmaceuticals During the Pandemic collected information from Canadians aged 18 years and older. Respondents were asked whether they needed (routine) dental care in the previous 12 months, whether they received that care, whether they experienced any mouth or tooth pain (indicative of a dental emergency), and whether and how COVID-19 affected service access. Results: Of the 44.5% of Canadians who reported needing dental care in the 12 months before the survey, 5.8% did not receive the care they reportedly needed. Almost 20% of those with a reported need had their appointment cancelled, rescheduled, or delayed because of COVID-19, and this was more common for individuals with unmet dental care needs (46.9%) than it was for those who had received dental care (17.1%). For those requiring more urgent care, 23.3% of Canadians experienced pain in their mouth or teeth in the previous 12 months. Among those with dental pain, 64.2% sought treatment, and the majority (86.4%) received the treatment they needed. One-third (33.2%) avoided care for their dental-related pain because of fear of contracting COVID-19. Interpretation: During the first year of the pandemic, many Canadians experienced cancelled or delayed dental services or did not receive the oral health care services they reportedly needed. Ongoing monitoring could help determine whether these COVID-19 service interruptions will have lasting effects on Canadians' oral health.

The local restaurant environment in relation to eating out and sugary drink intake among Canadian children and youth.

Background: Accessibility of food retail in communities may play a role in shaping the food choices of local residents. However, previous studies have shown mixed results. This study examined associations between the local restaurant environment and the frequency of eating food from restaurants and intake of sugary drinks among Canadian children and youth. Data and methods: The study cohort consisted of 23,776 participants (aged 1 to 17 years) in the 2019 Canadian Health Survey on Children and Youth who resided in large urban population centres across the Canadian provinces. Measures of geographic access to various restaurant types within walking distance of participants' residential areas came from the 2018 Canadian Food Environment Dataset. Poisson regression models with robust standard errors assessed associations between measures of absolute densities (number per km²) of full-service, fast-food and other restaurants, and the relative density of fast-food restaurants (as a percentage of total restaurants) with the frequency of eating food from fast-food or full-service restaurants and sugary drink intake in the previous seven days. Results: After adjustment for a range of sociodemographic covariates, there were no consistent associations between absolute and relative measures of restaurant access and the frequency of eating food from restaurants or intake of sugary drinks. Interpretation: Results reveal no consistent relationships between local restaurant exposures and the frequency of eating food from restaurants or sugary drink intake among Canadian children and youth. Efforts to create environments that foster healthy food choices among young people will remain important but will likely need to target multiple activity spaces beyond the local neighbourhood.

Household food insecurity in Canada early in the COVID-19 pandemic.

BACKGROUND: Food insecurity linked to insufficient income is an important determinant of health. Whether the COVID-19 pandemic has exacerbated levels of food insecurity in Canada, particularly among vulnerable groups, is unclear. This study estimated the proportion of Canadians reporting experience of household food insecurity six to nine months into the COVID-19 pandemic, and drew comparisons with pre-pandemic levels. DATA AND METHODS: Data on household food security status during the pandemic came from the population-based cross-sectional Canadian Community Health Survey (CCHS) collected from September to December 2020. Analyses were based on 26,831 respondents aged 12 and older residing in the 10 provinces. The Household Food Security Survey Module was used to categorize respondents' household food security status within the previous 12 months as food secure or marginally, moderately or severely insecure. The percentage of Canadians reporting some experience of household food insecurity was estimated for the overall population and for various sociodemographic groups. T-tests were used to draw comparisons with pre-pandemic rates from the 2017/2018 CCHS. RESULTS: In fall 2020, 9.6% of Canadians reported having experienced some level of food insecurity in their household in the prior 12 months, which is lower than the estimate of 12.6% from 2017/2018. Overall estimates were also lower in fall 2020 when examined within levels of household food insecurity (i.e., marginal, moderate or severe). The percentage of Canadians reporting experience of household food insecurity was either unchanged or lower than in 2017/2018 among sociodemographic groups vulnerable to experiencing income-related food insecurity, including renters and those with lower levels of education. INTERPRETATION: During the second wave of the COVID-19 pandemic in fall 2020, about 1 in 10 Canadians aged 12 and older reported experience of food insecurity in their household in the previous 12 months. This proportion was lower compared with 2017/2018, both overall and among several groups at higher risk of food insecurity. Monitoring household food insecurity will continue to be important during the COVID-19 pandemic and throughout the years of recovery ahead.

Linkage of the nationally representative Canadian Community Health Survey - Nutrition 2004 to routinely collected mortality records.

Introduction: The Canadian Community Health Survey (CCHS) - Nutrition 2004 (n=35,107; interview dates from January 2004 to January 2005) linked to the Canadian Vital Statistics - Death Database (CVSD) (2011) represents a novel linkage of a population-based, nationally representative nutrition survey with routinely collected mortality records (including date and cause of death). The linkage was done through individual tax data in Canada, and contains longitudinal records for 29,897 Canadians aged 0 years and older-1,753 of whom died-in the 10 provinces of Canada. The median follow-up time was 7.49 years, with 102,953 person-years among males and 114,876 person-years among females (unweighted), and included a special sampling survey weight (for linked data) to account for those who did not agree to share and link their information. The CCHS - Nutrition 2004 linked to CVSD has been used to evaluate associations between lifestyle and sociodemographic characteristics and mortality. Using these data, statistical methods have been developed and tested to control random and systematic measurement errors when evaluating the relationship between different dietary exposures (evaluated using repeated 24-hour dietary recalls) and health outcomes. The linked data are available through Statistics Canada's Research Data Centres.

Eating away from home in Canada: impact on dietary intake.

BACKGROUND: Public health measures related to the COVID-19 pandemic have upended the way Canadians eat and shop for food. Since the pandemic began, many Canadians have reported consuming food away from home (FAFH) less often. FAFH tends to be less healthful than food prepared at home. Little is known about patterns of Canadians' FAFH consumption before the pandemic. This study used 2015 national-level nutrition data, the most recent available, to characterize patterns of FAFH consumption and selected markers of dietary intake. DATA AND METHODS: National-level food intake data came from the first 24-hour dietary recall provided by 20,475 respondents aged 1 or older to the 2015 Canadian Community Health Survey-Nutrition. Mean daily intakes of selected food subgroups and nutrients, adjusted for total energy intake, were compared between those who had consumed any food in a restaurant on the previous day and those who had not. Estimates were generated overall and for eight age and sex groups. RESULTS: In 2015, overall, 21.8% of Canadians had consumed FAFH in a restaurant on the previous day. Eating out was most common among males aged 19 to 54 (27.7%) and least common among young children aged 1 to 5 (8.4%). Compared with Canadians who had not eaten out on the previous day, those who had eaten out had consumed, on that day, fewer servings of whole fruit; whole grains; dark green and orange vegetables; other vegetables (excluding potatoes); milk and fortified soy-based beverages; and legumes, nuts and seeds, on average. Those who had eaten out had consumed, on average, less fibre and total sugar, and more total fat, saturated fat and sodium on that day. There were few differences for meat and poultry, fish and seafood, and protein intake. DISCUSSION: On the day that Canadians ate out in a restaurant, their dietary intake was generally less favourable than that of Canadians who did not eat out. If Canadians continue to eat at home more and to consume less FAFH, as early pandemic-period reports suggest, then results can be used to gauge the potential dietary implications of these shifts.

Data profile: Expanding the research potential of the Canadian Health Measures Survey using paired respondent data.

The family environment is an important influence on the health and behaviours of children. Few large-scale datasets include detailed and objectively measured health data about multiple individuals from the same family who are living in the same household. The Canadian Health Measures Survey (CHMS) is a repeating, cross-sectional survey that selects two members of a household-a child and a randomly selected older member of the household aged 12 to 79 years-with at least one child aged 3 to 11 years in residence. These paired respondent records, available in the CHMS relationship files, provide unique opportunities to researchers interested in examining associations between two members of the same household for health behaviours and outcomes. A range of pairings are captured in the relationship files (e.g., parent and child, siblings, grandchild and grandparent) with birth parent-child pairs being the most common. These paired respondent data are an important analytical asset of the CHMS and enhance the research potential of the survey significantly.

Change in vegetable and fruit consumption in Canada between 2004 and 2015.

BACKGROUND: Eating plenty of vegetables and fruits on a daily basis is the foundation of a healthy diet. This study investigated patterns in Canadians' vegetable and fruit consumption in 2015 and compared these with 2004 data. DATA AND METHODS: The 2015 Canadian Community Health Survey (CCHS) - Nutrition and the 2004 CCHS - Nutrition (Cycle 2.2) provided nationally representative 24-hour dietary recall data on Canadians' vegetable and fruit intakes. The frequency of consumption and the average quantity of daily intake for total vegetables, fruits and subgroups were calculated overall and by age and sex group for each survey year. The National Cancer Institute's methodology was used to assess the distribution of usual total vegetable and fruit intake and how it relates to recommendations in the 2007 Canada's Food Guide. RESULTS: Overall, Canadians reported consuming fewer total servings of vegetables and fruits in 2015 (4.5 average daily servings) than in 2004 (5.3 average daily servings). Lower total fruit intakes were explained by significantly lower intakes of fruit juice across nearly all age and sex groups, resulting in a decline of 0.3 average total daily fruit servings in the overall population. Lower vegetable consumption was largely driven by lower intakes of potatoes and, to a lesser extent, lettuce. Intakes of whole fruits and other vegetables remained largely unchanged. In both years, the majority of Canadians did not usually consume the number of total vegetable and fruit servings recommended for their age and sex group in the 2007 Canada's Food Guide. DISCUSSION: Canadians reported consuming fewer vegetables and fruits in 2015 compared with 2004. This was largely driven by substantially lower consumption of fruit juice and, to a lesser extent, potatoes. These findings can serve as valuable baseline data to assess any changes in patterns of vegetable and fruit consumption in Canada.

Consumption of ultra-processed foods in Canada.

BACKGROUND: A larger share of ultra-processed foods and drinks (UPF) in the diet is increasingly linked with poor diet quality, weight gain and elevated risk of diet-related chronic disease. This study used 2015 national-level data, the most recent available, to characterize the intake of UPF among Canadians and to examine changes since 2004. DATA AND METHODS: The 2004 and 2015 Canadian Community Health Surveys provided 24-hour dietary recall data for Canadians aged 2 or older. All food and drink items were classified according to type of food processing using the NOVA classification. The mean energy contribution of UPF (as a percentage of total daily energy intake) was compared across survey years for the overall population and for eight age-sex groups. The National Cancer Institute's methodology was used to assess the distribution of usual energy contributed by UPF. RESULTS: On average, UPF contributed 47.8% (95% CI: 47.3% to 48.3%) of total daily energy in 2004 and 45.7% (95% CI: 45.0% to 46.4%) in 2015 among the overall population, and more than half of total daily energy among children and adolescents. Both the mean energy contribution of UPF and their usual energy distribution shifted downward since 2004 for all age-sex groups, except among adults aged 55 or older. The energy contributions of soft drinks, fruit juices and fruit drinks declined, particularly among children and adolescents. Ultra-processed breads contributed more energy in 2015 for nearly all age-sex groups. DISCUSSION: As in 2004, the overall dietary share of UPF in Canada remained high in 2015, but intakes of some UPF, particularly beverages, declined. The energy contribution of UPF remained highest among children and adolescents, and increased among adults aged 55 or older.

Changes in beverage consumption in Canada.

BACKGROUND: Beverage consumption, especially water, is critical to a healthy diet. The 2007 Canada's Food Guide (CFG) makes specific recommendations regarding the intake of water, fruit juice, milk and energy-dense beverages. Earlier comparisons of 2004 and 2015 dietary data show that changing patterns in beverage intake can explain some of the changes in energy and sugar intake observed in the Canadian population. The objective of this study is to describe any changes in beverage consumption between 2004 and 2015, and how these changes relate to existing recommendations in the 2007 CFG. DATA AND METHODS: Data are from the Canadian Community Health Survey - Nutrition for 2004 and 2015. To estimate any change in the proportion of Canadians consuming a beverage the day before and the quantity consumed, 19 beverage categories were derived using the Bureau of Nutritional Science categories. The CFG classification was used to estimate the relative share of juice intake from total servings of vegetables and fruit, and the intake of milk from milk subcategories. The National Cancer Institute method was used to estimate usual intake. RESULTS: Water intake was higher in 2015 than in 2004. Consumption of milk, fruit juice, and energy-dense beverages such as fruit drinks and soft drinks was lower in 2015. Changes in water, soft drink and fruit drink consumption mostly reflect changes in the proportion of Canadians consuming these specific beverages the day before reporting, while changes in milk and fruit juice mostly reflect a change in the quantity consumed. In 2015, the majority of the population was consuming more whole vegetables and fruit than juice, which is in line with 2007 CFG recommendations. DISCUSSION: Beverage consumption patterns in Canada changed between 2004 and 2015. Some of these changes are in line with recommendations from the 2007 CFG, the food guide that was available at the time of the 2015 survey.

Change in total sugars consumption among Canadian children and adults.

BACKGROUND: Free sugars are nutrients of public health concern that have been associated with negative health outcomes, including dental caries in children and excess weight gain. Since national-level free sugars data are not currently available for Canadians, total sugars intake was examined to understand sugars intake in the population. The objective of this analysis was to describe and compare total sugars consumption among Canadians in 2004 and 2015. DATA AND METHODS: Data are from the 2004 and 2015 Canadian Community Health Survey-Nutrition. Separate descriptive analyses of total sugars for children aged 2 to 18 (n=13,919) and adults aged 19 and older (n=31,156) were conducted by year and by misreporting status (under-, plausible and over-reporters), and the top sources of total sugars were identified. Misreporting status was studied to better understand differences in sugars intakes between survey years. T-tests were used to determine significant differences between survey years. RESULTS: In 2015, the average daily total sugars consumption was 101 grams (24 teaspoons) for children aged 1 to 8, 115 grams (27 teaspoons) for children aged 9 to 18, and 85 grams (20 teaspoons) for adults. Sugary beverages, taken together, were the top source of sugars for all age groups. Total sugars consumption decreased from 2004 to 2015 overall, although not by misreporting status. Total sugars from food alone increased from 2004 to 2015, and total sugars from beverages alone decreased, regardless of age or misreporting status. DISCUSSION: The overall decrease in total sugars consumption from 2004 to 2015 may be explained by changes in misreporting. Total sugars from food alone increased, while total sugars from beverages alone decreased. This was true for all age groups and for plausible reporters.

Comparison of self-reported and accelerometer-measured physical activity among Canadian youth.

BACKGROUND: Generally, correlation and agreement between self-reported and accelerometer-measured physical activity are low. The objective of this study is to compare estimates of physical activity from a newly developed Canadian questionnaire with measurements by accelerometer among 12- to 17-year-olds. DATA AND METHODS: Physical activity was self-reported by domain (transportation, recreation, school, and occupational/household) as part of the new Physical Activity Youth Questionnaire (PAYQ) in the Canadian Health Measures Survey (CHMS; 2014-2017; n = 975) and the Canadian Community Health Survey (CCHS; 2015-2016; n=7,619). The CHMS also collected moderate-to-vigorous physical activity (MVPA) data using the Actical accelerometer. Descriptive statistics and correlation and agreement analyses were used to compare and contrast self-reported and accelerometer-measured physical activity variables. Linear regression was used to assess the association between physical activity and obesity. RESULTS: The average daily MVPA measured by accelerometry was 49.7 minutes per day. According to the PAYQ, Canadian youth reported an average of 78.2 minutes of physical activity per day from all domains, including recreation (31.3 minutes per day), transportation (15.5 minutes per day), school (25.8 minutes per day), and occupational/household (5.6 minutes per day). According to accelerometer-measured MVPA, 23.1% of youth met the physical activity guideline. The inclusion of all domains of self-reported physical activity resulted in a higher percentage of youth meeting the physical activity guideline (58.6%) than was the case for the recreation domain only (18.5%) or the sum of the recreation and school domains (34.0%). Overall, self-reported and accelerometer-measured physical activity estimates were poorly correlated (R ⟨ 0.2). DISCUSSION: Population-level estimates of physical activity and the percentage of youth meeting the physical activity guideline were well-aligned between the Actical and the PAYQ; however, large differences were evident at the individual level. Therefore, caution should be exercised in using data from these two methods since their values may not be interchangeable.

Accounting for misreporting when comparing energy intake across time in Canada.

BACKGROUND: Estimates of energy intake are lower in 2015 compared with 2004. The difference observed is too large to be explained by a change in energy requirements or physical activity at the population level. Self-reported dietary intake is subject to misreporting and may explain part of this difference. The objectives of this study are to assess how misreporting has changed from 2004 to 2015 and to demonstrate how these changes may affect the interpretation of the national intake data of Canadians. DATA AND METHODS: Data from the 2004 Canadian Community Health Survey - Nutrition (CCHS - Nutrition) and the 2015 CCHS - Nutrition were used to estimate energy intake and requirements for all participants aged 2 or older. The ratio of energy intake to total energy expenditure requirements (EI:TEE) was used to categorize respondents as under-reporters (EI:TEE ⟨ 0.70), over-reporters (EI:TEE ⟩ 1.42) or plausible reporters (EI:TEE = 0.70 to 1.42). Descriptive analyses by category of respondent were conducted for respondents aged 2 or older who participated in the measured height and weight component. The main caloric sources that contributed to the difference in estimated energy requirements were used to show the impact of misreporting on the analysis. RESULTS: The prevalence of under-reporters was 7.5% higher in 2015 compared with 2004, while the prevalence of over-reporters was 7.4% lower. There was no change in the prevalence of plausible reporters. Estimated energy intake from participants categorized as plausible reporters showed a difference of 84 kcal from 2004 to 2015, compared with a difference of 250 kcal for the entire sample. Estimated energy intake was lower in 2015 compared with 2004 across all categories of respondents for many foods, including sugar-sweetened beverages and milk, and was higher for only pastries and nuts. DISCUSSION: Misreporting changes will affect analysis and should, at a minimum, be acknowledged when comparing 2015 with 2004. Using a comparable category of plausible reporters or adjusting for reporting status are options that will allow a better comparison of these two datasets.

Reallocating time between sleep, sedentary and active behaviours: Associations with obesity and health in Canadian adults.

BACKGROUND: Moderate-to-vigorous physical activity (MVPA) and sleep are positively associated with adults' health, while the association with sedentary behaviour (SED) is negative. Light-intensity physical activity (LPA) is emerging as an independent predictor of improved cardiovascular health. The health impacts of each of these factors have been examined in isolation, but interest has increased in associations between health and movement behaviours collectively. DATA AND METHODS: This analysis examines how reallocating time between movement behaviours is associated with obesity and with self-rated general and mental health. Data for 18- to 79-year-olds (n = 10,621) were collected from 2007 through 2015 as part of the Canadian Health Measures Survey. LPA, MVPA, and SED were measured using the Actical accelerometer. Body mass index (BMI) and waist circumference (WC) were directly measured. Sleep and general and mental health were self-reported. RESULTS: Reallocation of 30 minutes from SED, LPA or sleep to MVPA was associated with a lower BMI and smaller WC, particularly for older and overweight/obese individuals. Time reallocation from SED to LPA was associated with lower BMI and smaller WC in respondents who were aged 50 or older or who were overweight/obese. Time reallocated from SED to any other movement behaviour was associated with decreased odds of reporting poor/fair rather than excellent general health. Time reallocation from SED to LPA or to sleep, but not to MVPA, was associated with decreased odds of reporting poor/fair rather than excellent mental health. DISCUSSION: These findings confirm previous research indicating a strong association between MVPA and markers of obesity and health, particularly among older and overweight/obese individuals. This study also provides evidence that increasing LPA is an important health promotion message for these two subpopulations.

Comparison of self-reported and accelerometer-measured physical activity in Canadian adults.

BACKGROUND: Self-reported and accelerometer-measured physical activity levels generally exhibit low correlation and agreement. The objective of this study is to compare estimates of physical activity among adults from a newly developed Canadian questionnaire with those obtained objectively by accelerometry. DATA AND METHODS: Data for 18- to 79-year-olds (N = 2,372) were collected in 2014 and 2015 as part of the Canadian Health Measures Survey (CHMS). Moderate-to-vigorous physical activity (MVPA) was reported on the household questionnaire by domain (transportation, recreation, and occupational or household) as part of the new Physical Activity Adult Questionnaire (PAAQ) and measured objectively using the Actical accelerometer. Correlation and mean difference analyses were used to assess the relationships between measured and reported physical activity variables. Linear regression was used to test the association between measured and reported physical activity and measures of obesity. RESULTS: On average, Canadian adults reported more physical activity than they accumulated on an accelerometer (49 minutes versus 23 minutes per day). The highest correlation observed was between accelerometer-measured MVPA and the sum of self-reported recreation and transportation activity (R = 0.36, p ⟨ 0.0001). The sum of activity from all domains (recreation + transportation + occupational or household) exhibited a lower correlation with measured variables because the occupational or household domain was negatively correlated with MVPA (R = -0.04). The occupational or household domain was positively correlated with light-intensity physical activity (R = 0.20, p ⟨ 0.0001). Respondents in the least active quintile were more likely than those in the most active quintile to report more activity than was measured by the accelerometer. On average, the most active quintile reported less activity than was measured by the accelerometer. DISCUSSION: The newly developed Canadian physical activity questionnaire exhibited modest correlation and agreement with accelerometer-measured physical activity among adults. Accelerometers and questionnaires provide complementary information, about different aspects of physical activity (actual movement versus perceived time). Consequently, one should exercise caution in using estimates derived from these methods interchangeably.

Parent-Child association in body weight status.

BACKGROUND: The prevalence of overweight and obesity among children and adults has risen in Canada. Studies suggest that parent obesity is a risk factor for overweight and obesity in children. This analysis examines associations between biological parent and child body mass index (BMI) in a nationally representative sample of Canadian children. DATA AND METHODS: The analysis is based on data collected for 1,563 children aged 6 to 10 in the first three cycles of the Canadian Health Measures Survey (2007 to 2013). BMI was calculated using measured height and weight. Pearson correlation, logistic, and linear regression analyses examined associations between biological parent and child BMI and obesity status, controlling for other risk factors. RESULTS: Biological parent and child BMI were correlated. When risk factors were taken into account, a child's average BMI increased as their parent's BMI increased. Parent BMI explained 2% of the variance in boys' BMI and 12% of the variance in girls' BMI. Boys and girls with a biological parent who was obese were at increased risk of being overweight or obese. Girls were also at increased risk of being overweight or obese if a biological parent was overweight. INTERPRETATION: Children's body weight status is associated with that of at least one of their biological parents. Having an obese parent increases the risk of overweight or obesity among children in Canada.

Parent-Child association in physical activity and sedentary behaviour.

BACKGROUND: Parents influence the physical activity and sedentary behaviour of their children. This analysis examines associations between parental role modeling and support and children's physical activity and sedentary behaviour. DATA AND METHODS: The sample consists of 1,328 biological parent-child pairs from the first three cycles of the Canadian Health Measures Survey (2007 through 2013). Data on physical activity and sedentary behaviour were collected using a questionnaire and by accelerometer. Pearson correlation and linear regression analyses were completed to examine associations between parents' and children's measured physical activity and sedentary time and reported screen-based activities. Analyses were adjusted for variables indicating parental support and household lifestyle characteristics. RESULTS: Accelerometer-measured physical activity and sedentary time were correlated in all parent-child pairs. Parents' measured moderate-to-vigorous physical activity (MVPA) was associated with children's MVPA (ß = 0.28, p < 0.001). For every 20-minute increase in a parent's MVPA, the child's MVPA increased by 5 to 10 minutes. Parents' measured sedentary time was associated with that of their daughters on weekends, and with that of their sons during the after-school period. Parents' reported screen time was associated with that of their daughters. INTERPRETATION: This study confirms parents' influence on their children's physical activity. Parental role modeling and support have independent effects on a child's level of physical activity.

Physical activity of Canadian children and youth, 2007 to 2015.

BACKGROUND: This study describes and compares the percentages of Canadian children and youth who adhere to different operational definitions of the moderate-to-vigorous physical activity (MVPA) recommendation of 60 minutes per day. DATA AND METHODS: Data for 6- to 17-year-olds (n = 5,608) were collected from 2007 through 2015 as part of the Canadian Health Measures Survey. MVPA was measured using the Actical accelerometer. The MVPA recommendation was operationalized as accumulating 60 minutes of MVPA every day, on most days, and on average. RESULTS: Data from the most recent cycle of the Canadian Health Measures Survey indicate that 7% of children and youth accumulated at least 60 minutes of MVPA on at least 6 out of 7 days, and 33% achieved a weekly average of at least 60 minutes per day. Boys accumulated more MVPA than did girls, and 6- to 11-year-olds accumulated more MVPA than did 12- to 17-year-olds. Regardless of how adherence to the recommendation is operationalized, MVPA levels among Canadian children and youth did not change over the 9-year period from 2007 to 2015. INTERPRETATION: The majority of Canadian children do not meet the physical activity recommendation, regardless of the operational definition used. However, the discrepancies between results based on different interpretations of the 60-minutes-per-day recommendation highlight the importance of explicitly reporting how recommendations are operationalized to avoid misinterpreting trends and comparisons.

Overweight and obesity are associated with lower vitamin D status in Canadian children and adolescents.

INTRODUCTION: There is evidence that 25-hydroxyvitamin D levels are lower in overweight and obese youth. This study examined the relationship between weight status and 25-hydroxyvitamin D, while controlling for confounders, in Canadian youth. METHODS: Plasma 25-hydroxyvitamin D from subjects aged 6 to 17 years from the Canadian Health Measures Survey cycles 1 (2007 to 2009) and 2 (2009 to 2011) was used. Sex-specific multiple linear regression and logistic regressions examined the relationship of overweight and obesity (body mass index ≥ 85th percentile) with 25-hydroxyvitamin D levels and the odds of 25-hydroxyvitamin D <40 nmol/L and <50 nmol/L. RESULTS: The prevalence of risk of vitamin D deficiency (25-hydroxyvitamin D < 30 nmol/L) was 6% (95% confidence interval [CI] 3.26% to 10.12%). Vitamin D inadequacy, estimated by levels <40 nmol/L, was 15% (95% CI 10.34% to 20.39%; 19% [95% CI 13.1 to 25.6] for teenagers). Seventy per cent (95% CI 63.59 to 75.17) had levels >50 nmol/L, consistent with achieving the Recommended Dietary Allowance. In adjusted analyses, overweight/obesity (1/3 of subjects) was independently associated with lower 25-hydroxyvitamin D for both sexes after adjustment for age, race, income, season, vitamin D supplementation and daily milk consumption. For 25-hydroxyvitamin D <40 nmol/L, the overweight/obese odds ratio for males was 2.63 (95% CI 1.34 to 5.18). For 25-hydroxyvitamin D <50 nmol/L, overweight/obese odds ratios were 2.19 (95% CI 1.46 to 3.28) for males and 1.39 (95% CI 1.05 to 1.84) for females. CONCLUSIONS: This study confirms the inverse association between adiposity and serum concentrations of 25-hydroxyvitamin D in Canadian youth and the independent association of overweight/obesity to 25-hydroxyvitamin D level and vitamin D status after adjustment for other factors.

Using national dietary intake data to evaluate and adapt the US Diet History Questionnaire: the stepwise tailoring of an FFQ for Canadian use.

OBJECTIVE: To evaluate the Canadian Diet History Questionnaire I (C-DHQ I) food list and to adapt the US DHQ II for Canada using Canadian dietary survey data. DESIGN: Twenty-four-hour dietary recalls reported by adults in a national Canadian survey were analysed to create a food list corresponding to C-DHQ I food questions. The percentage contribution of the food list to the total survey intake of seventeen nutrients was used as the criterion to evaluate the suitability of the C-DHQ I to capture food intake in Canadian populations. The data were also analysed to identify foods and to modify portion sizes for the C-DHQ II. SETTING: The Canadian Community Health Survey (CCHS) - Cycle 2.2 Nutrition (2004). SUBJECTS: Adults (n 20 159) who completed 24 h dietary recalls during in-person interviews. RESULTS: Four thousand five hundred and thirty-three foods and recipes were grouped into 268 Food Groups, of which 212 corresponded to questions on the C-DHQ I. Nutrient intakes captured by the C-DHQ I ranged from 79 % for fat to 100 % for alcohol. For the new C-DHQ II, some food questions were retained from the original US DHQ II while others were added based on foods reported in CCHS and foods available on the Canadian market since 2004. Of 153 questions, 143 were associated with portion sizes of which fifty-three were modified from US values. Sex-specific nutrient profiles for the C-DHQ II nutrient database were derived using CCHS data. CONCLUSIONS: The C-DHQ I and II are designed to optimize the capture of foods consumed by Canadian populations.

Using a Betabinomial distribution to estimate the prevalence of adherence to physical activity guidelines among children and youth.

BACKGROUND: Estimates of the prevalence of adherence to physical activity guidelines in the population are generally the result of averaging individual probability of adherence based on the number of days people meet the guidelines and the number of days they are assessed. Given this number of active and inactive days (days assessed minus days active), the conditional probability of meeting the guidelines that has been used in the past is a Beta (1 + active days, 1 + inactive days) distribution assuming the probability p of a day being active is bounded by 0 and 1 and averages 50%. A change in the assumption about the distribution of p is required to better match the discrete nature of the data and to better assess the probability of adherence when the percentage of active days in the population differs from 50%. DATA AND METHODS: Using accelerometry data from the Canadian Health Measures Survey, the probability of adherence to physical activity guidelines is estimated using a conditional probability given the number of active and inactive days distributed as a Betabinomial(n, a + active days , ß + inactive days) assuming that p is randomly distributed as Beta(a, ß) where the parameters a and ß are estimated by maximum likelihood. RESULTS: The resulting Betabinomial distribution is discrete. For children aged 6 or older, the probability of meeting physical activity guidelines 7 out of 7 days is similar to published estimates. For pre-schoolers, the Betabinomial distribution yields higher estimates of adherence to the guidelines than the Beta distribution, in line with the probability of being active on any given day. INTERPRETATION: In estimating the probability of adherence to physical activity guidelines, the Betabinomial distribution has several advantages over the previously used Beta distribution. It is a discrete distribution and maximizes the richness of accelerometer data.